Perfluoroalkyl substances in circum-ArcticRangifer: caribou and reindeer

Abstract

Livers of caribou and reindeer (Rangifer tarandus) from Canada (n = 146), Greenland (n = 30), Svalbard (n = 7), and Sweden (n = 60) were analyzed for concentrations of eight perfluoroalkyl carboxylic acids and four perfluoroalkane sulfonic acids. In Canadian caribou, PFNA (range < 0.01-7.4 ng/g wet weight, ww) and PFUnDA (<0.01-5.6 ng/g ww) dominated, whereas PFOS predominated in samples from South Greenland, Svalbard, and Sweden, although the highest concentrations were found in caribou from Southwest Greenland (up to 28 ng/g ww). We found the highest median concentrations of all PFAS except PFHxS in Akia-Maniitsoq caribou (Southwest Greenland, PFOS 7.2-19 ng/g ww, median 15 ng/g ww). The highest concentrations of ΣPFAS were also found in Akia-Maniitoq caribou (101 ng/g ww) followed by the nearby Kangerlussuaq caribou (45 ng/g ww), where the largest airport in Greenland is situated, along with a former military base. Decreasing trends in concentrations were seen for PFOS in the one Canadian and three Swedish populations. Furthermore, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA showed decreasing trends in Canada's Porcupine caribou between 2005 and 2016. In Sweden, PFHxS increased in the reindeer from Norrbotten between 2003 and 2011. The reindeer from Västerbotten had higher concentrations of PFNA and lower concentrations of PFHxS in 2010 compared to 2002. Finally, we observed higher concentrations in 2010 compared to 2002 (albeit statistically insignificant) for PFHxS in Jämtland, while PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA showed no difference at all.

Keywords: Arctic terrestrial environment; Canada; Greenland; Long-range transport; PFAS; PFOS; Svalbard; Sweden.

Fig. 1

Map indicating the different sampling areas. Norrbotten = #12 North Sweden, Västerbotten = #13 north-central Sweden, and Jämtland = #14 central Sweden

Fig. 2

Box plots showing concentrations of PFNA, PFDA, PFUnDA, PFDoDA, PFHxS, and PFOS in fourteen caribou and reindeer populations. The horizontal thick lines show median values. The hinges represent the first and third quantile. The notches represent roughly 95% confidence interval for the median values. Outliers are shown in circles. From left to right: seven populations in Canada (CAN)—Klaza (n = 4), Porcupine (Porc, n = 65), Bluenose West (BN, n = 10), Bathurst (Bat, n = 7), Dolphin & Union (D&U, n = 10), Ahiak (Ahi, n = 10), Qamanirjuaq (Qam, n = 40); three populations in Greenland (GRL)—Akia-Maniitsoq (Akia, n = 10), Kangerlussuaq-Sisimiut (Kanger, n = 10), and Isortoq (SoGr, n = 10). Svalbard, Norway (Sval_NOR, n = 7); and finally three populations in Sweden (SWE)—Norrbotten (Norr, n = 20), Västerbotten (Vastb, n = 20), and Jämtland (Jamt, n = 20)

Fig. 2

Box plots showing concentrations of PFNA, PFDA, PFUnDA, PFDoDA, PFHxS, and PFOS in fourteen caribou and reindeer populations. The horizontal thick lines show median values. The hinges represent the first and third quantile. The notches represent roughly 95% confidence interval for the median values. Outliers are shown in circles. From left to right: seven populations in Canada (CAN)—Klaza (n = 4), Porcupine (Porc, n = 65), Bluenose West (BN, n = 10), Bathurst (Bat, n = 7), Dolphin & Union (D&U, n = 10), Ahiak (Ahi, n = 10), Qamanirjuaq (Qam, n = 40); three populations in Greenland (GRL)—Akia-Maniitsoq (Akia, n = 10), Kangerlussuaq-Sisimiut (Kanger, n = 10), and Isortoq (SoGr, n = 10). Svalbard, Norway (Sval_NOR, n = 7); and finally three populations in Sweden (SWE)—Norrbotten (Norr, n = 20), Västerbotten (Vastb, n = 20), and Jämtland (Jamt, n = 20)

Fig. 3

The pattern of PFAS compounds in liver tissue from caribou/reindeer indicating PFCA (i.e., PFNA, PFDA, and PDUnDA) dominated in the Canadian Arctic and western Greenland while PFSA (i.e., PFOS) dominated in Svalbard, Sweden, and Isortoq

Fig. 4

Time trends for PFDA, PFDoDA, PFTrDA, and PFOS in Porcupine caribou, NW, Canada, show significant yearly decreases of ca 10% except for PFTrDA (only 3% yearly decrease). PFNA and PFUnDA show decreasing trends, however not statistically significant. The solid red line represents a log linear regression and the dashed red line a 3-year smoother. Open circles represent individuals and filled circles are the annual median OBS The titles of the first two graphs are missing! Should read "Porc_CAN PFNA and Porc_CAN PFDA